Programming and Graphics

7.6 Graph animation 231

return 0;

}

The three dots indicate previously listed blocks of code.

When the graph is drawn on the screen, the program waits for a key to
be pressedwhile the cursor is on the graphics window. When the “q” key is
pressed, the program issues a prompt for postscript drawing options and file
name. If any other key is pressed, the execution quits.

Problems

7.5.1. Run codeplot2dto produce a postscript file containing the graph of a

function of your choice.

7.5.2. Modify codeplot2dto allow for multiple functions printed on the same

graph with different colors.

7.6 Graph animation

As a further application, we discuss a code contained in the filegraph2danm.cc
that animates a specified time-dependent function:

/*------------------------

graph2danm.cc

Animate an evolving function

-------------------------*/

#include<iostream>

#include<cmath>

#include "VOGLE/voglec++.h"

#include "drawmarker2d.h"

#include "drawline2d.h"

#include "drawaxes2d.h"

using namespace std;

char kbd;

int main()

{

float points[4][2];

//--- Define the data:

const int n=32;